Belt worn control system and battery for the percutaneous model of the Jarvik 2000 heart

A belt worn controller and lithium-ion battery pack have been developed for use with the initial clinical trials of the Jarvik 2000 heart. Patient int erface considerations, safety, and simplicity were major design inputs for the system. The controller was developed using all analog technology to avo id difficulties with electromagnetic interference (EMI), to minimize suscep tibility to electrostatic discharge, and to avoid the need for software val idation. Manual control of pump speed is accomplished by a patient operated knob, according to physician instructions for rest and exercise for each i ndividual patient. The system includes alarms and indicators which show the following: the amount of remaining battery charge, if the battery is low a nd needs replacement, the power in watts being consumed, if the power consu med is above 15 W, if the pump is running below the selected speed setting, and if the pump stops. The control box, curved to be worn on the belt, is only 2.5 inches high for comfort when sitting. The battery pack, also form fitted for patient comfort, weighs just over 1 1/2 pounds and supplies 65 W -h of energy storage, sufficient to run the device for over 8 h at nominal load.